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Biomedical subjects

Frank Rauch

Publications and source records attributed to Frank Rauch.

At least 19 recordsLinked to original sources
PubMed2004

Delayed osteotomy but not fracture healing in pediatric osteogenesis imperfecta patients receiving pamidronate.

UNLABELLED: This study evaluated factors influencing fracture (n = 197) and osteotomy (n = 200) healing in children with moderate to severe OI. Pamidronate treatment was associated with delayed healing after osteotomy, but not after fracture. The data suggest that both pamidronate and mechanical factors influence bone healing in this cohort. INTRODUCTION: Intravenous pamidronate is widely used to treat children with moderate to severe osteogenesis imperfecta (OI). However, the effect of this treatment on bone healing is not well characterized. We therefore retrospectively analyzed the healing of lower limb fractures and osteotomies in children with moderate to severe OI, both before and after the start of pamidronate treatment. MATERIALS AND METHODS: Bone healing was evaluated on standard radiographs after 197 lower limb fractures (132 femur and 65 tibia) in 82 patients (age at fracture, 0.0-19.9 years) and 200 intramedullary rodding procedures in 79 patients (age at surgery, 1.2-19.8 years). Delayed healing was diagnosed when a fracture or osteotomy line was at least partially visible 12 months after the event. RESULTS: Delayed fracture healing was observed more frequently during than before pamidronate treatment. However, the effect of pamidronate was no longer significant when age differences were taken into account (odds ratio [OR], 1.76; 95% CI, 0.61-5.10). Better mobility status was a strong independent predictor of delayed healing after fractures that occurred during pamidronate treatment. After osteotomies, delayed healing was more frequent when pamidronate had been started before surgery (OR, 7.29; 95% CI, 2.62-20.3), and this effect persisted after adjustment for multiple confounders. During pamidronate treatment, older age (OR per year of age, 1.25; 95% CI, 1.06-1.47) and osteotomy of the tibia (OR, 3.51; 95% CI, 1.57-7.82) were independent predictors of delayed healing. CONCLUSIONS: This study suggests that pamidronate therapy is associated with delayed healing of osteotomy sites after intramedullary rodding procedures. Better mobility status, but not pamidronate treatment, seems to be predictive of delayed healing after fractures.

Absorptiometry, Photon↗
PubMed2004

Maternal and fetal outcome after long-term pamidronate treatment before conception: a report of two cases.

The pregnancies of two women with osteogenesis imperfecta who received intravenous pamidronate before conception are reported. The mothers suffered no ill effects. One baby had transient asymptomatic hypocalcemia and one had bilateral talipes equinovarus. This report documents the pregnancy outcomes of two women with osteogenesis imperfecta (OI), types I and IV, who received intravenous pamidronate as part of an observational trial before conception. Pamidronate was not administered after conception. Other than hyperemesis in one woman, the pregnancies and deliveries were uneventful. Both babies inherited OI from their mothers. The baby with OI type IV also had bilateral talipes equinovarus. Biochemical evaluation of the mothers and babies at 24 h and/or 2 weeks postpartum was normal, apart from one baby with asymptomatic hypocalcemia at 24 h of age that had resolved when next measured on day 11 of life. No biochemistry was available on the second child until 13 days of age. Neither baby had skeletal modeling abnormalities consistent with in utero pamidronate exposure. The lumbar spine (L1-L4) areal BMD and anterior to posterior height ratios of lumbar vertebral bodies of both women remained constant during pregnancy. Both the mothers and babies remain well and free of fracture 14 and 16 months postpartum.

Adult↗
PubMed2004

Osteogenesis imperfecta.

Osteogenesis imperfecta is a genetic disorder of increased bone fragility, low bone mass, and other connective-tissue manifestations. The most frequently used classification outlines four clinical types, which we have expanded to seven distinct types. In most patients the disorder is caused by mutations in one of the two genes encoding collagen type 1, but in some individuals no such mutations are detectable. The most important therapeutic advance is the introduction of bisphosphonate treatment for moderate to severe forms of osteogenesis imperfecta. However, at present, the best treatment regimen and the long-term outcomes of bisphosphonate therapy are unknown. Although this treatment does not constitute a cure, it is an adjunct to physiotherapy, rehabilitation, and orthopaedic care. Gene-based therapy presently remains in the early stages of preclinical research.

Bone and Bones↗
PubMed2004

The 'muscle-bone unit' during the pubertal growth spurt.

Mechanostat theory postulates that developmental changes in bone strength are secondary to the increasing loads imposed by larger muscle forces. Therefore, the increase in muscle strength should precede the increase in bone strength. We tested this prediction using densitometric surrogate measures of muscle force (lean body mass, LBM) and bone strength (bone mineral content, BMC) in a study on 70 boys and 68 girls who were longitudinally examined during pubertal development. On the level of the total body, the peak in LBM accrual preceded the peak in BMC accretion by an average of 0.51 years in girls and by 0.36 years in boys. In the arms, the maximal increase in LBM was followed by arm peak BMC accrual after an interval of 0.71 years in girls and 0.63 years in boys. In the lower extremities, the maximal increase in LBM was followed by peak BMC accrual after an interval of 0.22 years in girls and 0.48 years in boys. A multiple regression model revealed that total body peak LBM velocity, but not peak height velocity and sex, was independently associated with total body peak BMC velocity (r(2) = 0.50; P < 0.001). Similarly, arm and leg peak LBM velocity, but not peak height velocity and sex, were independently associated with arm and leg peak BMC velocity, respectively (r(2) = 0.61 for arms, r(2) = 0.41 for legs; P < 0.001 in both cases). These results are compatible with the view that bone development is driven by muscle development, although the data do not exclude the hypothesis that the two processes are independently determined by genetic mechanisms.

Adolescent↗
PubMed2004

Respiratory distress with pamidronate treatment in infants with severe osteogenesis imperfecta.

This report aims to describe the adverse respiratory events associated with the first pamidronate cycle in four infants with severe osteogenesis imperfecta (OI) who were less than 2 years of age. Fifty-nine infants with severe OI were commenced on cyclical intravenous pamidronate therapy in an observation trial. Routine observations were measured during each infusion cycle. During the first treatment cycle, four infants (7%) with preexisting respiratory compromise developed respiratory distress. The respiratory distress was successfully managed with bronchodilator therapy. Two of the infants required intensive care admission. There was no recurrence of respiratory distress with subsequent pamidronate infusion cycles. In infants with severe OI and preexisting respiratory compromise, the first pamidronate infusion cycle may be associated with an acute deterioration of respiratory function. The etiology is unclear but may involve cytokine release and/or hemodynamic compromise from fluid administration during the first infusion cycle. Close monitoring throughout the first treatment cycle is of paramount importance.

Diphosphonates↗
PubMed2004

Three children with lower limb fractures and a mineralization defect: a novel bone fragility disorder?

In this report, we describe three unrelated children with an apparently novel bone fragility disorder that is associated with an idiopathic mineralization defect. Recurrent lower limb fractures started with weight bearing. The patients had none of the phenotypic, radiological, or histomorphometric features classically associated with known bone fragility disorders such as osteogenesis imperfecta (OI), idiopathic juvenile osteoporosis (IJO), or mild autosomal dominant osteopetrosis. Radiologically, there was increased metaphyseal trabeculation, normal to increased cortical thickness, and no evidence of rickets or osteomalacia. Areal and volumetric bone mineral density (BMD) of the lumbar spine did not show any major alteration. Peripheral quantitative computed tomography of the radius showed elevated cortical thickness and total and trabecular volumetric bone mineral density in one patient. Qualitative histology of iliac bone biopsy specimens showed a paucity of the birefringent pattern of normal lamellar bone. Quantitative histomorphometric analysis demonstrated osteomalacia with a prolonged mineralization lag time in the presence of a decreased mineral apposition rate. There was no biochemical evidence of abnormal calcium or phosphate metabolism. Type I collagen mutation analysis was negative. We conclude that this is a bone fragility disorder of moderate severity that tends to cause fractures in the lower extremities and is associated with the accumulation of osteoid due to an intrinsic mineralization defect. The pathogenetic basis for this disorder remains to be elucidated.

Adolescent↗
PubMed2003

Effects of osteogenic protein-1 on distraction osteogenesis in rabbits.

In this study we tested the effect of locally applied osteogenic protein 1 (OP-1) on distraction osteogenesis in rabbits. Seven days after tibial osteotomy, distraction was started at a rate of 0.25 mm per 12 h for 3 weeks. At the end of the distraction period, OP-1 was injected at the site of osteotomy. Four different dosages were tested (0, 80, 800, or 2000 microg; eight rabbits per dose group). Rabbits were sacrificed 3 weeks later, and histologic, densitometric, and biomechanical parameters were assessed. No significant differences were found between groups for any parameter. To explain why this approach was only modestly successful, the expression of BMP receptor protein in the newly formed tissue was analyzed by immunohistochemistry. Strong expression of BMP receptor IA, IB, and II was found during the early distraction phase, but not during later stages of the process. Thus, it appears that the lack of receptor protein in the target tissue impairs the effect of OP-1 given at the end of the distraction period. Possibly, OP-1 could be more useful when applied early in the distraction phase.

Animals↗
PubMed2003

Expression of bone morphogenetic proteins during mandibular distraction osteogenesis.

Distraction osteogenesis is a form of in vivo tissue engineering in which the gradual separation of cut bone edges results in the generation of new bone. In this study, the temporal and spatial expression of bone morphogenetic proteins (BMPs) 2, 4, and 7 was examined in a rabbit model of mandibular distraction osteogenesis. Fourteen skeletally mature male rabbits were studied. After osteotomy, a distractor was applied to one side of the mandible. After 1 week of latency, distraction was initiated at 0.25 mm every 12 hours for 3 weeks (distraction period), followed by a 3-week consolidation period. Two animals were killed each week after surgery. The generate bone was analyzed for the expression of BMP-2, -4, and -7 by using standard bone histological and immunohistochemical techniques. BMP-2 and -4 were highly expressed in osteoblastic cells during the distraction period and in chondrocytes during the consolidation period. BMP-7 demonstrated relatively minor expression in osteoblastic cells during the distraction period. All BMPs were strongly expressed in vascularized connective tissue during the distraction period. These data indicate that BMPs participate in the translation of mechanical stimuli into a biological response during mandibular distraction osteogenesis.

Animals↗
PubMed2003

Osteogenesis imperfecta types I, III, and IV: effect of pamidronate therapy on bone and mineral metabolism.

Cyclical iv therapy with pamidronate improves the clinical course in children and adolescents with osteogenesis imperfecta (OI). In this study we evaluated the effect of this therapy on bone and mineral metabolism in 165 patients with OI types I, III, and IV (age, 2 wk to 17.9 yr; 86 girls and 79 boys). All patients received iv pamidronate infusions on 3 successive days, administered at age-dependent intervals of 2-4 months. During the 3 d of the first infusion cycle, serum concentrations of ionized calcium dropped by 0.14 +/- 0.008 mmol (mean +/- SE; P < 0.001), and serum PTH levels transiently almost doubled (P < 0.001). At the same time, urinary excretion of the bone resorption marker type I collagen N-telopeptide related to creatinine (uNTX/uCr) decreased by 61-73% (P < 0.001). Two to 4 months later, ionized calcium had returned to pretreatment levels, and uNTX/uCr remained 30-35% lower than at baseline (P < 0.001). During 4 yr of pamidronate therapy (n = 40 patients), ionized calcium levels remained stable, but PTH levels increased by about 30% (P < 0.01). uNTX/uCr, expressed as a percentage of the age- and sex-specific mean value in healthy children, decreased from 132 +/- 13% (mean +/- SE) at baseline to 49 +/- 3% after 4 yr of therapy (P < 0.001). In conclusion, serum calcium levels can decrease considerably during and after pamidronate infusions, requiring close monitoring especially at the first infusion cycle. In long-term therapy, bone turnover is suppressed to levels lower than those in healthy children. The consequences of chronically low bone turnover in children with OI are unknown at present.

Adolescent↗
PubMed2003

Effect of pamidronate treatment in children with polyostotic fibrous dysplasia of bone.

Intravenous infusions with the bisphosphonate compound pamidronate decrease bone pain and reportedly can lead to refilling of dysplastic lesions in adults with fibrous dysplasia (FD) of bone. Here we describe the effects of this treatment approach in 18 children and adolescents (age at start of therapy, 6.2-17.5 yr; eight girls) with polyostotic FD, who received pamidronate for 1.2-9.1 yr (median, 3.8 yr). Treatment cycles with pamidronate (1-1.5 mg/kg.d on 3 consecutive days) were given every 4 months. Levels of serum alkaline phosphatase and urinary collagen type I N-telopeptide were elevated at baseline and decreased continuously during the first 3 yr of therapy. There was no radiographic evidence of filling of lytic lesions or thickening of the bone cortex surrounding the lesions in any patient. Histomorphometric results in dysplastic bone tissue of patients receiving pamidronate (n = 7; time of therapy, 1.4-4.8 yr) were similar to those of patients without medical therapy (n = 9). No serious side effects were noted. In conclusion, pamidronate therapy appears to be safe in children and adolescents with polyostotic FD. However, we found no clear evidence that pamidronate has an effect on dysplastic lesions in such patients.

Adolescent↗
PubMed2003

Bone mass, size, and density in children and adolescents with osteogenesis imperfecta: effect of intravenous pamidronate therapy.

Cyclical intravenous therapy with pamidronate improves the clinical course in children and adolescents with osteogenesis imperfecta (OI). In this study, we evaluated the effect of this therapy on lumbar spine bone mass (bone mineral content [BMC]), size (bone volume [BV]), and density (volumetric bone mineral density [vBMD]). Results from 56 patients (age, 0.2-15.9 years; 25 girls) on long-term pamidronate treatment were compared with those of 167 patients who had not received pamidronate before densitometry. In all patients who received pamidronate, BMC, BV, and vBMD increased above levels expected for untreated patients (p < 0.001 in each case). After 4 years of treatment, BMC, BV, and vBMD were 154%, 44%, and 65% higher, respectively, in treated than in untreated patients who were matched for age and OI type. A multiple regression model showed that baseline BMC was negatively associated with the increase in BMC. In conclusion, the bone mass increase in pediatric OI patients receiving pamidronate is caused by increases in both bone size and density. Patients with larger deficits in bone mass at baseline have a more marked bone mass gain during therapy.

Adolescent↗
PubMed2003

Height and weight development during four years of therapy with cyclical intravenous pamidronate in children and adolescents with osteogenesis imperfecta types I, III, and IV.

OBJECTIVES: Treatment with pamidronate improves the clinical course in children with osteogenesis imperfecta (OI), but theoretically might affect longitudinal growth. In this study we analyzed growth during cyclical intravenous pamidronate treatment in children and adolescents (age.04-15.6 years at baseline) with moderate to severe forms of OI types I, III, and IV. METHODS: The effect of 1 year of pamidronate treatment on height and weight was analyzed in 116 patients (OI-I, N = 29; OI-III, N = 42; OI-IV, N = 45). The results of 4 years of therapy were evaluated in 41 children (OI-I, N = 12; OI-III, N = 14; OI-IV, N = 15). RESULTS: Baseline height was low for age in all OI types. After 1 year of pamidronate therapy, height z scores had increased significantly in OI-III (by 0.3 +/- 0.8, mean +/- standard deviation; P =.04) and did not change in OI-I and OI-IV. Weight z scores increased significantly in OI-I (by 0.2 +/- 0.4, P =.01). After 4 years of pamidronate therapy, mean height z scores increased significantly in OI-IV (by 0.41 +/- 0.71, P =.04), whereas nonsignificant trends to increase were found for OI-I and OI-III. When height was expressed as a percentage of the result expected for untreated patients with the same OI type, long-term pamidronate therapy was associated with a significant height gain in all 3 OI types (P <.001). Eight patients who reached final height after 3.0 +/- 1.0 years of treatment were taller on average than expected for untreated patients (P =.04). CONCLUSIONS: Four years of cyclical intravenous pamidronate treatment led to a significant height gain in moderately to severely affected OI patients.

Adolescent↗
PubMed2003

Rapid increase in grip force after start of pamidronate therapy in children and adolescents with severe osteogenesis imperfecta.

OBJECTIVE: To examine changes in grip force during pamidronate therapy in children and adolescents with severe osteogenesis imperfecta (OI). METHODS: Maximal isometric grip force of the nondominant hand was prospectively determined in 42 patients (age at the start of the study: 7.3-15.9 years; 18 girls) with severe forms of OI. Patients were treated with intravenous pamidronate infusions given in 4 monthly cycles, each cycle consisting of 3 infusions (1 mg pamidronate/kg body wt) on 3 successive days. RESULTS: At the start of pamidronate therapy, grip force was low compared with age-specific reference data (age z score mean +/- standard deviation: -2.7 +/- 2.1) but was normal for weight (weight z score: -0.1 +/- 1.8). Four months after the first pamidronate infusion cycle, grip force had increased significantly, whether related to age (age z score: -2.0 +/- 1.8) or to weight (weight z score: 0.6 +/- 1.5). At 2 years after the start of therapy, grip force z scores were not significantly different from the 4-month results. CONCLUSIONS: Maximal isometric grip force markedly increases after a single cycle of intravenous pamidronate in children with severe forms of OI, and this gain in grip force is maintained for at least 2 years.

Adolescent↗
PubMed2002

The muscle-bone relationship: methods and management - perspectives in glycogen storage disease.

UNLABELLED: Currently bone development is commonly presented as a process leading to the 'accumulation of peak bone mass'. Consequently, the usual approach to a suspected bone disorder in a child is to address the question are this child's bones as heavy as those of a healthy child of the same sex and age? However, from a functional perspective the aim of bone development should not be make bones as heavy as possible but to make them as stable as necessary. A functionally oriented approach should address two different questions: how strong are the bones? are they as strong as they need to be? It is clear that the bone has to be strong enough to withstand the mechanical forces to which it is exposed. CONCLUSION: since the main forces applied to bones are due to muscle action, the strength of a bone should be related to the force of the muscles attached to it.

Bone Density↗